1. Field of the Invention
The present invention relates to a developing device utilized in an image forming apparatus such as an electrophotographic or electrostatic recording type copying machine, printer, facsimile, or the like.
2. Description of the Related Art
A known image forming apparatus such as a laser beam printer, copying machine, or the like, incorporates a process cartridge that can be easily mounted to and dismounted from the apparatus body. The process cartridge incorporates in a unitary structure process units such as a photosensitive drum serving as a latent image carrying- member, a charger, a developing device, cleaner means, and the like.
FIG. 8 is a cross sectional view of a conventional process cartridge. Toner T.sub.11 in a toner container 11 is conveyed toward a development roller 9b by means of a conveying member 9a. When the amount of toner is increased in order to prolong the life of such a cartridge, sufficient stirring of the toner cannot be achieved by the conveying member 9a alone.
A possible solution to this problem is to increase the toner conveying capability in the container by placing a plurality of the toner conveying members 9a as illustrated in FIGS. 9A and 9B.
However, in such a construction, more toner in the process cartridge may lead to poor toner circulation, so that the image begins to fade as the copying or printing operation is continued in the apparatus body.